Engine/lib/bullet/src/BulletCollision/NarrowPhaseCollision/btPersistentManifold.h

   1 /*
   2 Bullet Continuous Collision Detection and Physics Library
   3 Copyright (c) 2003-2006 Erwin Coumans  http://continuousphysics.com/Bullet/
   4
   5 This software is provided 'as-is', without any express or implied warranty.
   6 In no event will the authors be held liable for any damages arising from the use of this software.
   7 Permission is granted to anyone to use this software for any purpose,
   8 including commercial applications, and to alter it and redistribute it freely,
   9 subject to the following restrictions:
  10
  11 1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
  12 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
  13 3. This notice may not be removed or altered from any source distribution.
  14 */
  15
  16 #ifndef BT_PERSISTENT_MANIFOLD_H
  17 #define BT_PERSISTENT_MANIFOLD_H
  18
  19
  20 #include "LinearMath/btVector3.h"
  21 #include "LinearMath/btTransform.h"
  22 #include "btManifoldPoint.h"
  23 class btCollisionObject;
  24 #include "LinearMath/btAlignedAllocator.h"
  25
  26 struct btCollisionResult;
  27
  28 ///maximum contact breaking and merging threshold
  29 extern btScalar gContactBreakingThreshold;
  30
  31 typedef bool (*ContactDestroyedCallback)(void* userPersistentData);
  32 typedef bool (*ContactProcessedCallback)(btManifoldPoint& cp,void* body0,void* body1);
  33 extern ContactDestroyedCallback gContactDestroyedCallback;
  34 extern ContactProcessedCallback gContactProcessedCallback;
  35
  36 //the enum starts at 1024 to avoid type conflicts with btTypedConstraint
  37 enum btContactManifoldTypes
  38 {
  39         MIN_CONTACT_MANIFOLD_TYPE = 1024,
  40         BT_PERSISTENT_MANIFOLD_TYPE
  41 };
  42
  43 #define MANIFOLD_CACHE_SIZE 4
  44
  45 ///btPersistentManifold is a contact point cache, it stays persistent as long as objects are overlapping in the broadphase.
  46 ///Those contact points are created by the collision narrow phase.
  47 ///The cache can be empty, or hold 1,2,3 or 4 points. Some collision algorithms (GJK) might only add one point at a time.
  48 ///updates/refreshes old contact points, and throw them away if necessary (distance becomes too large)
  49 ///reduces the cache to 4 points, when more then 4 points are added, using following rules:
  50 ///the contact point with deepest penetration is always kept, and it tries to maximuze the area covered by the points
  51 ///note that some pairs of objects might have more then one contact manifold.
  52
  53
  54 ATTRIBUTE_ALIGNED128( class) btPersistentManifold : public btTypedObject
  55 //ATTRIBUTE_ALIGNED16( class) btPersistentManifold : public btTypedObject
  56 {
  57
  58         btManifoldPoint m_pointCache[MANIFOLD_CACHE_SIZE];
  59
  60         /// this two body pointers can point to the physics rigidbody class.
  61         const btCollisionObject* m_body0;
  62         const btCollisionObject* m_body1;
  63
  64         int     m_cachedPoints;
  65
  66         btScalar        m_contactBreakingThreshold;
  67         btScalar        m_contactProcessingThreshold;
  68
  69
  70         /// sort cached points so most isolated points come first
  71         int     sortCachedPoints(const btManifoldPoint& pt);
  72
  73         int             findContactPoint(const btManifoldPoint* unUsed, int numUnused,const btManifoldPoint& pt);
  74
  75 public:
  76
  77         BT_DECLARE_ALIGNED_ALLOCATOR();
  78
  79         int     m_companionIdA;
  80         int     m_companionIdB;
  81
  82         int m_index1a;
  83
  84         btPersistentManifold();
  85
  86         btPersistentManifold(const btCollisionObject* body0,const btCollisionObject* body1,int , btScalar contactBreakingThreshold,btScalar contactProcessingThreshold)
  87                 : btTypedObject(BT_PERSISTENT_MANIFOLD_TYPE),
  88         m_body0(body0),m_body1(body1),m_cachedPoints(0),
  89                 m_contactBreakingThreshold(contactBreakingThreshold),
  90                 m_contactProcessingThreshold(contactProcessingThreshold)
  91         {
  92         }
  93
  94         SIMD_FORCE_INLINE const btCollisionObject* getBody0() const { return m_body0;}
  95         SIMD_FORCE_INLINE const btCollisionObject* getBody1() const { return m_body1;}
  96
  97         void    setBodies(const btCollisionObject* body0,const btCollisionObject* body1)
  98         {
  99                 m_body0 = body0;
 100                 m_body1 = body1;
 101         }
 102
 103         void clearUserCache(btManifoldPoint& pt);
 104
 105 #ifdef DEBUG_PERSISTENCY
 106         void    DebugPersistency();
 107 #endif //
 108
 109         SIMD_FORCE_INLINE int   getNumContacts() const { return m_cachedPoints;}
 110         /// the setNumContacts API is usually not used, except when you gather/fill all contacts manually
 111         void setNumContacts(int cachedPoints)
 112         {
 113                 m_cachedPoints = cachedPoints;
 114         }
 115
 116
 117         SIMD_FORCE_INLINE const btManifoldPoint& getContactPoint(int index) const
 118         {
 119                 btAssert(index < m_cachedPoints);
 120                 return m_pointCache[index];
 121         }
 122
 123         SIMD_FORCE_INLINE btManifoldPoint& getContactPoint(int index)
 124         {
 125                 btAssert(index < m_cachedPoints);
 126                 return m_pointCache[index];
 127         }
 128
 129         ///@todo: get this margin from the current physics / collision environment
 130         btScalar        getContactBreakingThreshold() const;
 131
 132         btScalar        getContactProcessingThreshold() const
 133         {
 134                 return m_contactProcessingThreshold;
 135         }
 136
 137         void setContactBreakingThreshold(btScalar contactBreakingThreshold)
 138         {
 139                 m_contactBreakingThreshold = contactBreakingThreshold;
 140         }
 141
 142         void setContactProcessingThreshold(btScalar     contactProcessingThreshold)
 143         {
 144                 m_contactProcessingThreshold = contactProcessingThreshold;
 145         }
 146
 147
 148
 149
 150         int getCacheEntry(const btManifoldPoint& newPoint) const;
 151
 152         int addManifoldPoint( const btManifoldPoint& newPoint, bool isPredictive=false);
 153
 154         void removeContactPoint (int index)
 155         {
 156                 clearUserCache(m_pointCache[index]);
 157
 158                 int lastUsedIndex = getNumContacts() - 1;
 159 //              m_pointCache[index] = m_pointCache[lastUsedIndex];
 160                 if(index != lastUsedIndex)
 161                 {
 162                         m_pointCache[index] = m_pointCache[lastUsedIndex];
 163                         //get rid of duplicated userPersistentData pointer
 164                         m_pointCache[lastUsedIndex].m_userPersistentData = 0;
 165                         m_pointCache[lastUsedIndex].m_appliedImpulse = 0.f;
 166                         m_pointCache[lastUsedIndex].m_contactPointFlags = 0;
 167                         m_pointCache[lastUsedIndex].m_appliedImpulseLateral1 = 0.f;
 168                         m_pointCache[lastUsedIndex].m_appliedImpulseLateral2 = 0.f;
 169                         m_pointCache[lastUsedIndex].m_lifeTime = 0;
 170                 }
 171
 172                 btAssert(m_pointCache[lastUsedIndex].m_userPersistentData==0);
 173                 m_cachedPoints--;
 174         }
 175         void replaceContactPoint(const btManifoldPoint& newPoint,int insertIndex)
 176         {
 177                 btAssert(validContactDistance(newPoint));
 178
 179 #define MAINTAIN_PERSISTENCY 1
 180 #ifdef MAINTAIN_PERSISTENCY
 181                 int     lifeTime = m_pointCache[insertIndex].getLifeTime();
 182                 btScalar        appliedImpulse = m_pointCache[insertIndex].m_appliedImpulse;
 183                 btScalar        appliedLateralImpulse1 = m_pointCache[insertIndex].m_appliedImpulseLateral1;
 184                 btScalar        appliedLateralImpulse2 = m_pointCache[insertIndex].m_appliedImpulseLateral2;
 185 //              bool isLateralFrictionInitialized = m_pointCache[insertIndex].m_lateralFrictionInitialized;
 186
 187
 188
 189                 btAssert(lifeTime>=0);
 190                 void* cache = m_pointCache[insertIndex].m_userPersistentData;
 191
 192                 m_pointCache[insertIndex] = newPoint;
 193                 m_pointCache[insertIndex].m_userPersistentData = cache;
 194                 m_pointCache[insertIndex].m_appliedImpulse = appliedImpulse;
 195                 m_pointCache[insertIndex].m_appliedImpulseLateral1 = appliedLateralImpulse1;
 196                 m_pointCache[insertIndex].m_appliedImpulseLateral2 = appliedLateralImpulse2;
 197
 198
 199                 m_pointCache[insertIndex].m_lifeTime = lifeTime;
 200 #else
 201                 clearUserCache(m_pointCache[insertIndex]);
 202                 m_pointCache[insertIndex] = newPoint;
 203
 204 #endif
 205         }
 206
 207
 208         bool validContactDistance(const btManifoldPoint& pt) const
 209         {
 210                 return pt.m_distance1 <= getContactBreakingThreshold();
 211         }
 212         /// calculated new worldspace coordinates and depth, and reject points that exceed the collision margin
 213         void    refreshContactPoints(  const btTransform& trA,const btTransform& trB);
 214
 215
 216         SIMD_FORCE_INLINE       void    clearManifold()
 217         {
 218                 int i;
 219                 for (i=0;i<m_cachedPoints;i++)
 220                 {
 221                         clearUserCache(m_pointCache[i]);
 222                 }
 223                 m_cachedPoints = 0;
 224         }
 225
 226
 227
 228 }
 229 ;
 230
 231
 232
 233
 234
 235 #endif //BT_PERSISTENT_MANIFOLD_H